bsw@2: slot.put_into("title", _"Diff")
bsw@2: 
bsw@2: local old_draft_id = param.get("old_draft_id", atom.integer)
bsw@2: local new_draft_id = param.get("new_draft_id", atom.integer)
bsw@2: 
bsw@10: if not old_draft_id or not new_draft_id then
bsw@10:   slot.put( _"Please choose two versions of the draft to compare")
bsw@10:   return
bsw@10: end
bsw@10: 
bsw@10: if old_draft_id == new_draft_id then
bsw@10:   slot.put( _"Please choose two different versions of the draft to compare")
bsw@10:   return
bsw@10: end
bsw@10: 
bsw@2: if old_draft_id > new_draft_id then
bsw@2:   local tmp = old_draft_id
bsw@2:   old_draft_id = new_draft_id
bsw@2:   new_draft_id = tmp
bsw@2: end
bsw@2: 
bsw@2: local old_draft = Draft:by_id(old_draft_id)
bsw@2: local new_draft = Draft:by_id(new_draft_id)
bsw@2: 
bsw@2: local key = multirand.string(26, "123456789bcdfghjklmnpqrstvwxyz");
bsw@2: 
bsw@2: local old_draft_filename = encode.file_path(request.get_app_basepath(), 'tmp', "diff-" .. key .. "-old.tmp")
bsw@2: local new_draft_filename = encode.file_path(request.get_app_basepath(), 'tmp', "diff-" .. key .. "-new.tmp")
bsw@2: 
bsw@2: local old_draft_file = assert(io.open(old_draft_filename, "w"))
bsw@2: old_draft_file:write(old_draft.content)
bsw@2: old_draft_file:write("\n")
bsw@2: old_draft_file:close()
bsw@2: 
bsw@2: local new_draft_file = assert(io.open(new_draft_filename, "w"))
bsw@2: new_draft_file:write(new_draft.content)
bsw@2: new_draft_file:write("\n")
bsw@2: new_draft_file:close()
bsw@2: 
bsw@2: local output, err, status = os.pfilter(nil, "sh", "-c", "diff -U 100000 '" .. old_draft_filename .. "' '" .. new_draft_filename .. "' | grep -v ^--- | grep -v ^+++ | grep -v ^@")
bsw@2: 
bsw@2: os.remove(old_draft_filename)
bsw@2: os.remove(new_draft_filename)
bsw@2: 
bsw@2: if not status then
bsw@2:   ui.field.text{ value = _"The drafts do not differ" }
bsw@2: else
bsw@2:   slot.put('<table class="diff">')
bsw@2:   slot.put('<tr><th width="50%">' .. _"Old draft revision" .. '</th><th width="50%">' .. _"New draft revision" .. '</th></tr>')
bsw@39: 
bsw@2:   local last_state = "unchanged"
bsw@2:   local lines = {}
bsw@2:   local removed_lines = nil
bsw@39: 
bsw@39:   local function process_line(line)
bsw@2:     local state = "unchanged"
bsw@2:     local char = line:sub(1,1)
bsw@2:     line = line:sub(2)
bsw@2:     state = "unchanged"
bsw@2:     if char == "-" then
bsw@2:       state = "-"
bsw@2:     elseif char == "+" then
bsw@2:       state = "+"
bsw@39:     elseif char == "!" then
bsw@39:       state = "eof"
bsw@2:     end
bsw@2:     if last_state == "unchanged" then
bsw@2:       if state == "unchanged" then
bsw@2:         lines[#lines+1] = line
bsw@39:       elseif (state == "-") or (state == "+") or (state == "eof") then
bsw@39:         local text = table.concat(lines, "\n")
bsw@40:         slot.put("<tr><td>", encode.html_newlines(encode.html(text)), "</td><td>", encode.html_newlines(encode.html(text)), "</td></tr>")
bsw@2:         lines = { line }
bsw@2:       end
bsw@2:     elseif last_state == "-" then
bsw@2:       if state == "-" then
bsw@2:         lines[#lines+1] = line
bsw@2:       elseif state == "+" then
bsw@2:         removed_lines = lines
bsw@2:         lines = { line }
bsw@39:       elseif (state == "unchanged") or (state == "eof") then
bsw@39:         local text = table.concat(lines,"\n")
bsw@39:         slot.put('<tr><td class="removed">', encode.html_newlines(encode.html(text)), "</td><td></td></tr>")
bsw@2:         lines = { line }
bsw@2:       end
bsw@2:     elseif last_state == "+" then
bsw@2:       if state == "+" then
bsw@2:         lines[#lines+1] = line
bsw@39:       elseif (state == "-") or (state == "unchanged") or (state == "eof") then
bsw@2:         if removed_lines then
bsw@39:           local text = table.concat(lines, "\n")
bsw@39:           local removed_text = table.concat(removed_lines, "\n")
bsw@39:           slot.put('<tr><td class="removed">', encode.html_newlines(encode.html(removed_text)), '</td><td class="added">', encode.html_newlines(encode.html(text)), "</td></tr>")
bsw@2:         else
bsw@39:           local text = table.concat(lines, "\n")
bsw@39:           slot.put('<tr><td></td><td class="added">', encode.html_newlines(encode.html(text)), "</td></tr>")
bsw@2:         end
bsw@2:         removed_lines = nil
bsw@2:         lines = { line }
bsw@2:       end
bsw@2:     end
bsw@2:     last_state = state
bsw@39:   end
bsw@39: 
bsw@39:   output = output .. " "
bsw@39:   output = output:gsub("[^\n\r]+", function(line)
bsw@39:     process_line(line)
bsw@2:   end)
bsw@39:   process_line("!")
bsw@39: 
bsw@2:   slot.put("</table>")
bsw@2: end 
bsw@2: